Collaborative Research: Characterization of Transport Properties and Microstructures of Battery Electrolytes via In Situ Spectroscopy

在化学、生物工程、环境和运输系统部门电化学系统项目的支持下，研究人员将开发创新的原位技术来表征可充电电池的液体电解质。可充电电池是电子产品、电动汽车、电网储能最流行的储能装置之一。下一代充电电池需要在快速充电和安全方面具有出色的性能。这项工作将为表征对电池性能至关重要的电解质的传输特性和微观结构提供通用方法。研究人员将把电池研究纳入本科生和研究生的教学课程中，鼓励 STEM 中代表性不足群体的学生参与研究，并通过外展活动扩大研究的影响，例如与当地学校教师举办 K-12 科学教育研讨会。这项工作的主要目标是开发各种通用的原位技术来表征电池电解质的输运特性和微观结构，包括原位探针束偏转 (PBD)，原位小角 X 射线散射 (SAXS)、欧姆显微镜和微电极阵列。具体来说，原位PBD将用于测量浓溶液理论框架中的迁移数和扩散率。只需一次实验即可确定电解质的迁移数和扩散率，而传统方法需要结合三到四次电化学实验。原位 PBD 还可以监测运行电池中电解质的离子浓度分布。原位 SAXS 将用于表征浓缩电解质的微观结构，并监测电场引起的离子对和/或聚集体的变化。欧姆显微镜将用于测量电导率并监测强电场引起的电荷分离引起的电解质电导率的变化。微电极阵列将用于同时测量电解质的离子浓度和扩散率。其他补充技术，包括拉曼光谱和分子动力学模拟，将提供对微观结构和传输特性之间相关性的分子水平理解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support from the Electrochemical Systems program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems, the investigators will develop innovative in situ techniques to characterize the liquid electrolyte for rechargeable batteries. Rechargeable batteries are one of the most popular energy storage devices for electronic products, electric vehicles, and grid energy storage. The next generation of rechargeable batteries requires excellent performance in terms of fast charging and safety. This work will provide universal methods to characterize the transport property and microstructure of the electrolyte crucial to battery performance. The investigators will incorporate the battery research into their teaching curricula for undergraduate and graduate students, encourage students from underrepresented groups in STEM to participate in the research, and broaden the impact of the research through outreach activities, e.g., workshops with local school teachers on K-12 science education.The primary objectives of this work are to develop a variety of universal in situ techniques to characterize the transport property and microstructure of battery electrolytes, including in situ probe beam deflection (PBD), in situ small-angle X-ray scattering (SAXS), ohmic microscopy, and microelectrode array. Specifically, in situ PBD will be employed to measure the transference number and diffusivity in the framework of concentrated solution theory. It only requires one experiment to determine the transference number and diffusivity of the electrolyte, while traditional methods will require the combination of three or four electrochemical experiments. In situ PBD can also monitor the ionic concentration profile of the electrolyte in an operating battery. In situ SAXS will be used to characterize the microscopic structure of the concentrated electrolyte and monitor the variation of ion pairs and/or aggregates induced by the electric field. Ohmic Microscopy will be utilized to measure the conductivity and monitor the variation of electrolyte conductivity resulting from the charge separation induced by the strong electric field. A microelectrode array will be used to measure the ionic concentration and diffusivity of the electrolyte simultaneously. The other complementary techniques, including Raman spectroscopy and molecular dynamics simulation, will provide a molecular-level understanding of the correlation between the microstructure and transport property.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.